Expanding tool



Feb. 1, 1966 w. J. PINEAU 3,232,011

EXPANDING TOOL Filed July 5, 1963 Q INVEN WILFRED J. PlNEAU 4 mm, MM? MWATTORNEYS 3,232,011 EXPANDING TOOL Wilfred Jay Pinean, Dearborn, Mich.assignor to Calumet & Hecla, Inc., Allen Park, Mich, a corporation ofMichigan 1 Filed July 5, 1963, Ser. No. 293,088 20 Claims. (Cl. 51-1373)The present invention relates to an expanding too-1, and moreparticularly to a pneumatically actuated expanding tool for grinding,polishing, and lapping tubing inside diameters or cylindrical bores.

It is an object of the present invention to provide an expandable toolemploying abrasive cloth or paper which may be inserted into a tube orthe like, and expanded to provide a controlled radial force or pressureon the inner surface of the tube while the tool is linearly advanced andretracted and/or rotated or oscillated back and forth about itslongitudinal axis.

' More specifically, it is an object of the present invention to providea tool as described in the preceding paragraph in which expansion. ofthe tool is accomplished pneumatically and in which means are providedfor blowing air through the tool to cool the same and to exhaustparticles of abrasive dust and the like from a tube in which the tool isemployed;

. Still more specifically, it is an object of the present invention toprovide a tool which includes -a radially expandable bladder, means forexposing an outer surface of the bladder at the periphery of the tool,means for supporting abrasive sheet material over the surface of thebladder, means for applying air under controlled pressure to theinterior of the bl-adder to press the abrasive, material againsttheeinner surface of a tube or the like withacontrolled force. j

Other objects and features of the invention will become apparent as thedescription proceeds, especially when taken in conjunction with theaccompanying drawing,

United States Patent approximately 40 to 50 thousandth-s of an inch.

illustrating a preferred embodiment of the invention,

wherein:

FIGURE 1 is a broken longitudinal section through the tool. i

. FIGURE 2 is a section on the line 2-2, FIGURE 1.

FIGURE 3 is a side elevation with parts in section of the housing. 7

FIGURE 4 is a section on the line 44, FIGURE 3. The tool disclosedherein is intended to be used in grinding, polishing, lapping," orotherwise operating on the inner surface of a tube oran elongatedcylinder and is designed particularly to permit accurate control ofradial pressure irrespective of the length of the tube. As best seen inFIGURES 1 and 2, a portion of a tube in which the tool is illustrated inoperating position is indicated at T and the tool indicated generally at10 is carried at the end of a drive tube 12 which may of course be ofany required length so that the tool may be employed to finish theinterior surface of elongated tubes.

p The tool 10 comprises a housing 14, details of which are best seen inFIGURES 3 and 4. The housing 14 comprises an initially generallycylindrical central portion 16 one side ofwhich is cut away as indicatedat 17 to leave a lateral opening extending substantially the full lengthof the central portion of the housing and having a, width substantiallyequal to the inside diameter of the housing. At opposite ends thehousingis provided with exteriorly threaded portions 18 and 19.

Received within the intermediate portion of the housing 14 is anexpandable bladder 24 which may for example be a length of gum rubbertubing. The ends of the expandable bladder 24 are sealed and for thispurpose there is provided an end cap 26 having a central plug 28 shapedto be received within an end of the tubular bladder 24. The end cap 26includes an internally threaded flange 30 adapted to engage the threadedend 20 of the housing. At the other end of the housing there is provideda plug 32 shaped to be received within the other end of the tubularbladder 24 and having a passage 34 extending therethrough. The plug 32includes a reduced neck portion 36 grooved to receive an O-ring 38.

a A drive cap 40 is provided having an internally threaded cylindricalflange 42 adapted to be threaded on the reduced threaded end portion 19of the housing. The drive cap at its opposite end includes a threadedportion 44 adapted to be screwed to 'the internally threaded end portionof the drive tube 12. The exterior endof the drive tube 12 is unthreadedand provides a smooth interior cylindrical surface fitting closely withthe exterior surface of the reduced end portion 46 of the drive cap 40.The reduced end portion 46 is grooved to receive the sealing O-ring 48.

Means are provided for employing the air used to expand the bladder 24in cooling of the tool and in blowing abrasive particles and the likeahead of the tool. For this purpose the drive cap 40 is provided with aplurality of inclined air passages 50 which communicate with airchambers 52, the latter being connected by passages 54 with alongitudinal air passage 56 extending through the drive cap 40. Theouter ends of the chambers 52 are threaded to receive jet adjustmentscrews 58. In practice, three air chambers 52 and passages *50arepreferred, and in FIGURE 2 it may be considered that the lower chamber52 is displaced from its actual position for clarity. In addition, thelowermost jet adjustment screw 58 as illustrated in FIGURE 2, is inclosed position but in practice the plurality of jet adjustment screwswill normally be set at the same adjustment. It will be apparent thatthe air under pressure passes through the inclinedv passages 50 and canmove ahead of the tool 10 through passages 60 provided between the outersurface of the housing 14 and the inner surface of the abrasive sheetmaterial 62.

The housing 14 is provided with an elongated slot 20 to receive an edgeof an abrasive sheet as'will subsequently be described. In addition, atits outer surface 7 Theabrasive material may be of any suitable type butexcellent results are obtained using a pressure sensitive abrasive clothor screen including open meshes which assist in maintaining the cloth inclean, efiicient condition as a result of air cleaning.

From the foregoing description it will be apparent that air admittedthrough the drive tube 12 passes through passages 56 and 34 into theinterior of the expandable bladder 24, thus forcing it radiallyoutwardly through the cut way portion 17 of the housing 14, as bestindicated in FIGURE 2. The abrasive sheet material has one edge receivedin the slot 20 and extends substantially completely around theintermediate portion of the housing 14. The pressure of the bladder 24acts directly against the inner surface of the abrasive sheet materialin 10 laterally so that pressure will also be applied to the PatentedFeb. 1, 1966 inner surface of the sheet material 62 by the pad 21. Thus,operating pressure is applied to the sheet material over a veryconsiderable area, approximately 180 degrees in angular extent asillustrated. Moreover, the above described action tends to balance thetool in the bore of the tube T.

In operation the tool may be rotated and reciprocated as required, thesemotions being imparted of course by appropriate mechanism connected tothe drive tube 12. Overheating as a result of friction is prevented bythe provision of cooling air passing through the passages 50 and thisair also tends to maintain the abrasive sheet material in cleaneflieient operating condition and also serves to blow abrasiveparticles, dust and the like out of the tube.

Since the force applied to the abrasive sheet material is controllableby the pressure existing within the bladder, this force is of courseaccurately controllable by available means such for example as anadjustable pressure regulating valve which is diagrammatically indicatedat 64. Moreover, since air pressure is employed to control the operatingpressure of the abrasive sheet material, and since this air pressure isadmitted to the tool 10 through the drive tube 12, the tube 12 may be ofany practical length without adversely alfeeting the accuracy of controlof the operating pressures.

The drawing and the foregoing specification constitute a description ofthe improved pneumatically expanding tool in such full, clear, conciseand exact terms as to enable any person skilled in the art to practicethe invention, the scope of which is indicated by the appended claims.

I claim:

1. A tool comprising a head, a closed chamber therein having a radiallymovable wall, means for supporting flexible sheet material in positionoverlying said wall, means for continuously supplying air undercontrolled pressure to said chamber, continuously open air passage meansin said head providing a continuous flow of air through said head fromsaid chamber to the exterior thereof, and means forming air passagesfrom one end of said head to the other between said sheet material andthe exterior surface of said head.

2. A tool as defined in claim 1 in which said passage means are inclinedto provide a longitudinal component to the direction of discharge of airfrom said passage means.

3. A tool as defined in claim 1 in which said passage means are adjacentone end of said head and inclined radially outwardly and toward theopposite end of said head.

4. A tool for engaging the inner surface of a tube and adapted forconnection to an elongated drive tube, said tool having an elongatedgenerally cylindrical head having a central chamber therein open at oneside thereof, a flexible closed bladded in said chamber having itsinterior in communication with the interior of said drive tube andadapted to have a lateral portion thereof move laterally outwardlythrough the side opening of said chamber, means for supporting aflexible abrasive sheet on said head overlying the lateral portion ofsaid bladder, said bladder being effective to press the abrasive sheetmaterial against the inner surface of the tube at a pressure determinedby fluid pressure within the bladder and drive tube.

5. A tool as defined in claim 4 comprising means for adjustablycontrolling the fluid pressure within said drive tube.

6. A tool for engaging the inner surface of a tube and adapted forconnection to an elongated drive tube, said tool having an elongatedgenerally cylindrical head having a central chamber therein open at oneside thereof, a flexible closed bladder in said chamber having itsinterior in communication with the interior of said drive tube andadapted to have a lateral portion thereof move laterally outwardlythrough the side opening of said chamber, a yieldable pad of extensivearea on said head at the side opposite the open side thereof, means forsup: porting a flexible abrasive sheet on said head overlying thelateral portion of said bladder and said pad, said bladder beingeffective to press the abrasive sheet material against the inner surfaceof the tube at a pressure determined by fluid pressure within thebladder and drive tube- 7. A tool for engaging the inner surface of atube and adapted for connection to an elongated drive tube, said toolhaving an elongated generally cylindrical head having a central chambertherein open at one side thereof, a flexible closed bladder in saidchamber having its interior in communication with the interior of saiddrive tube and adapted to have a lateral portion thereof move laterallyoutwardly through the side opening of said chamber, means for supportinga flexible abrasive sheet on said head overlying the lateral portion ofsaid bladder, said bladder being effective to press the abrasive sheetiaterial against the inner surface of the tube at a pressure determinedby fluid pressure within the bladder and drive tube, and air passagemeans in said head opening at the side of said head.

8. A tool as defined in claim '7 in which said passage means areinclined to project air forwardly of said head in the tube in which thehead is operating.

9. A tool comprising an elongated generally cylindrical head, having aninterior chamber open at one side, a flexible bladder in said chamberhaving a portion displaceable radially outwardly through the open sideof said chamber by interior pressure, a yieldable pad on said head atthe side opposite its open side, means for supporting a flexibleabrasive sheet over said pad and over the portion of said bladder insaid open side, and air supply means for supplying said bladder with airunder pressure.

it). A tool comprising an elongated generally cylindrical head, havingan interior chamber open at one side, a flexible bladder in said chamberhaving a portion displaceable radially outwardly through the open sideof said chamber by interior pressure, a yieldable pad on said head atthe side opposite its open side, means for supporting a flexibleabrasive sheet over said pad and over the portion of said bladder insaid open side, and air supply means for supplying said bladder with airunder pressure, said head having air passage means connected to said airsupply means and opening at the side of said head.

11. A tool as defined in claim It) in which said air passage means areinclined forwardly.

12. A tool comprising an elongated generally cylindrical head, having aninterior chamber open at one side, a flexible bladder in said chamberhaving a portion displace able radially outwardly through the open sideof said chamber by interior pressure, a yieldable pad on said head atthe side opposite its open side, means for supporting a flexibleabrasive sheet over said pad and over the portion of said bladder insaid open side, and air supply means for supplying said bladder with airunder pressure, said air supply means comprising a drive tube connectedto said head for mechanical actuation thereof in a tube.

13. A tool comprising an elongated tubular housing having threaded endsand having an elongated opening at one side thereof terminating short ofthe threaded ends, a flexible tubular bladder in said housing, a capthreaded to one end of said housing having a plug received within oneend of said bladder, a tubular plug received within the other end ofsaid bladder, said plugs and bladder defining an expansible chamber, adrive cap threaded to the other end of said housing, a drive tubeconnected to said drive cap, an air passage extending through said drivecap and communicating with said tubular plug to carry air under pressurefrom said drive tube to said chamber, said housing having means thereonfor supporting an edge of a sheet of flexible abrasive material inposition to overlie the opening in said housing.

14. A tool as defined in claim 13, said bladder being of resilientlyyieldable material.

15. A tool as defined in claim 13, said drive cap having inclined airpassage means extending from its air passage to its side surface.

16. A tool as defined in claim 13, a yieldab'le pad on the side of saidhousing opposite said opening, and a sheet of abrasive materialextending over the portion of said bladder in said opening'and over saidpad.

17. A tool as defined in claim 16, said pad being formed of sheet rubberpermanently bonded to said housing.

18. A tool as defined in claim 16, the portion of said bladder in saidopening extending beyond said opening and cooperating with said pad toposition said housing in centered position in a tube spaced laterallyinwardly from the inner surface of the portion of said abrasive sheetmaterial in the zones intermediate said pad and opening to provide forair flow longitudinally over said housing and forwardly of said head. r1

19. A tool comprising a generally cylindrical head having a chambertherein, a tubular drive shaft connected to one end of said head, meansfor continuously supplying air under controlled pressure to said chamberthrough said shaft, said chamberhaving at least one radially mov- I.SPENCER OVERHOLSER, LESTER and between said sheet material and said headfrom the said one end of said head to the other, and a. continuouslyopen air pass-age at the said one end of said head and connected to saidchamber at one end and inclined outwardly and toward the other end ofsaid head.

20. A tool as defined in claim 19 in which said head has a compressiblepad of limited circumferential extent on the exterior thereof at theside opposite said movable wall, said pad and said wall extendingradially outwardly beyond intervening portions of said head to definelongitudinal air channels closed at the outer sides thereof when thehead is inserted into a tube to polish the interior thereof. 7

References Cited by the Examiner UNITED STATES PATENTS 2, 146,195 2/1939Schultz 51-1841 2,490,472 12/1949 Raske 51-492 2,601,048 6/1952 Monger51-192 FOREIGN PATENTS 457,503 1 1/ 1936 Great Britain.

ROBERT C. RIORDON, Primary Examiner.

M. SWINGLE, Examiners.

1. A TOOL COMPRISING A HEAD, A CLOSED CHAMBER THEREIN HAVING A RADIALLYMOVABLE WALL, MEANS FOR SUPPORTING FLEXIBLE SHEET MATERIAL IN POSITIONOVERLYING SAID WALL, MEANS FOR CONTINUOUSLY SUPPLYING AIR UNDERCONTROLLED PRESSURE TO SAID CHAMBER, CONTINUOUSLY OPEN AIR PASSAGE MEANSIN SAID HEAD PROVIDING A CONTINUOUS FLOW OF AIR